5828 GLENWOOD AVE CINGULAR WIRELESS ANTENNA Geotech Report 2022-10-25 (2)

Adapt Engineering Sub grades and Testing: Regardless of location or material,all structural fill should be placed over firm, unyielding subgrade soils. We recommend that a representative from Adapt be retained to observe the condition of subgrade soils before fill placement begins, and to perform a series of in-place density tests during soil fill placement. In this way, the adequacy of soil compaction efforts may be evaluated as earthwork progresses. Fines Content: Soils used for structural fill should not contain individual particles greater than about 6 inches in diameter and should be free of organics, debris, and other deleterious materials. Given these prerequisites,the suitability of soils used for structural fill depends primarily on the grain-size distribution and moisture content of the soils when they are placed. When the "fmes" content (that soil fraction passing the U.S. No. 200 Sieve) increases, soils become more sensitive to small changes in moisture content. Soils containing more than about 5 percent fmes(by weight)cannot be consistently compacted to a firm, unyielding condition when the moisture content is more than about 2 percentage points above optimum. The possible fill,relic topsoil and sandy silt encountered in the test boring should be considered to be highly moisture sensitive. The poorly graded sand with gravel encountered deeper in the test boring should be considered to be moderately moisture sensitive. The use of"clean" soil is necessary for fill placement during wet-weather site work, or if the in-situ moisture content of the sandy site soils is too high to allow adequate compaction. Clean soils are defined as granular soils that have a fmes content of less than 5 percent(by weight)based on the soil fraction passing the U.S. 3/4-inch Sieve. CLOSURE We have prepared this report for use by the owner/developer and other members of the design and construction team for the proposed WA6348 Glenwood tower site. The opinions and recommendations contained within this report are not intended to be, nor should they be, construed as a warranty of subsurface conditions,but are forwarded to assist in the planning and design process. We have made observations based on our explorations that indicate the soil conditions at only those specific locations and only to the depths penetrated. These observations do not necessarily reflect soil types,strata thickness,or water level variations that may exist in other locations. If subsurface conditions vary from those encountered in our site exploration, Adapt should be alerted to the change in conditions so that we may provide additional geotechnical recommendations, if necessary. The future performance and integrity of the improvements will depend largely on proper initial site preparation, drainage, and construction procedures. Observation by experienced geotechnical personnel should be considered an integral part of the construction process. The conclusions and recommendations contained in this report are based on our understanding of the currently proposed project, as derived from written and verbal information supplied to us by General Dynamics. When the design has been fmalized, we recommend that we review the design and specifications to see that our recommendations have been interpreted and implemented as intended. If design changes are made,we request that we be retained to review our conclusions and recommendations and to provide a written modification or verification. AT&T Mobility do General Dynamics October 10,2016 Adapt Project No.WA16-20654-GEO Vagegas S\ 120